SpringBoot 2.0 报错: Failed to con

问题描述

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Spring Boot项目中含有Mybatis,打Jar包运行之后,报如下错误.

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class


Action:

Consider the following:
    If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
    If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

问题分析及解决方案

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问题原因: Mybatis没有找到合适的加载类,其实是大部分spring - datasource - url没有加载成功,分析原因如下所示.

1. DataSourceAutoConfiguration会自动加载.

2. 没有配置spring - datasource - url 属性.

3. spring - datasource - url 配置的地址格式有问题.

4. 配置 spring - datasource - url的文件没有加载.

网上给出了这几种解决方案.

方案一 (解决原因1)

排除此类的autoconfig。启动以后就可以正常运行。

@SpringBootApplication(exclude= {DataSourceAutoConfiguration.class})

方案二 (解决原因2)

在application.properties/或者application.yml文件中没有添加数据库配置信息.

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/read_data?useUnicode=true&characterEncoding=UTF-8&useSSL=false
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver

方案三 (解决原因3)

在spring xml配置文件中引用了数据库地址 所以需要对:等进行转义处理.但是在application.properties/或者application.yml文件并不需要转义,错误和正确方法写在下面了.

//错误示例
spring.datasource.url = jdbc:mysql\://192.168.0.20\:1504/f_me?setUnicode=true&characterEncoding=utf8

//正确示例
spring.datasource.url = jdbc:mysql://192.168.0.20:1504/f_me?setUnicode=true&characterEncoding=utf8

方案四 (解决原因4)

yml或者properties文件没有被扫描到,需要在pom文件中<build></build>添加如下.来保证文件都能正常被扫描到并且加载成功.

<!-- 如果不添加此节点mybatis的mapper.xml文件都会被漏掉。 -->
<resources>
    <resource>
        <directory>src/main/java</directory>
        <includes>
            <include>**/*.yml</include>
            <include>**/*.properties</include>
            <include>**/*.xml</include>
        </includes>
        <filtering>false</filtering>
    </resource>
    <resource>
        <directory>src/main/resources</directory>
        <includes>
            <include>**/*.yml</include>
            <include>**/*.properties</include>
            <include>**/*.xml</include>
        </includes>
        <filtering>false</filtering>
    </resource>
</resources>

说明

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我的问题是有原因4造成的,没有正确加载文件,其他方案均未认证其正确性,所以需要自行酌情而定.切勿盲目而为.